EDIT: The Frame Extraction feature has been fixed. Easily a 5/5 recommendation.

Viewhance has a lot of functionality and fun features that all generally work well. Though my one gripe that keeps me from giving it a full five stars is that its frame extraction function does not work properly anymore thanks to more recent Firefox updates. If you left click and try to get full frames, you come back with nothing. Right click and it all comes out a glitchy mess. It's a real shame too because there doesn't seem to be any other add-ons with this sort of feature apart from Google Chrome's "GIF Scrubber".